Of course, you should always be learning new technologies and tools. But that part's obvious, so I'm not going to give it attention here.
I have two pieces of advice for you.
The first is: Develop your sales and storytelling ability.
The second is: Follow the money.
One of the challenges of selling yourself as a SysAdmin, is that when you do your job properly, things just work. This makes you almost invisible... Generally, people only "notice" SysAdmins, when something is broken: builds fail, a website slows down, a web service times out, mail starts bouncing, etc. To improve your trajectory, you need to relentlessly train your ability to show the key people in your organization your successes. (As a side benefit, having this information organized is also highly useful to you if you decide to shop for a new gig.) Think constantly about how to tell the stories of your work, aided by stats and ideally, quotes from colleagues. I recommend reading the Phoenix Project for a bit of insight about this. There's a character in that story (Brent) who is the go-to devOps pro, but most people in the organization don't realize how critical he is. This is a classical failure in self-marketing. The company would literally fall apart if he wasn't there, and yet he's working longer hours than anyone else and probably getting paid about the same as his much less competent colleagues.
You also need to follow the money. In every business, there are certain things that terrify senior management. Perhaps it's failing a SOX or audit or losing PCI compliance. Maybe it's a breach of customer or patient data. Perhaps it's having a key piece of infrastructure go offline. Move yourself as close as you can to those business-critical elements. One of my projects is maintaining a scheduling application for some very expensive medical imaging equipment for a federal agency. These machines price out in the millions of dollars, and are shared by more than 30 research groups. Having even one of them go offline represents a huge cost to the organization. When I interviewed with them, there was basically zero push-back about price or hourly rate. All they cared about was how reliably I could keep these machines online. If I pitch them on some ideas which will improve reliability or disaster response, they are, of course, very receptive. That is the kind of infrastructure you want to be close to. Figure out what keeps your CxO's up at night, and find ways to make those problems go away.
Depending on your organization, these two things will improve your trajectory to a point. You may start to reach a ceiling in terms of income, as they may have a mental block with paying a sysadmin above, say, $150k/yr. If you want to reach higher, you may need to make the jump to working for your self. At that point, you probably want to find a better term for what you do than "SysAdmin". Labels such as "Scalability Specialst", "BI Consultant", or "Critical Infrastructure First Responder" might help you with positioning in such a way to command more respect and income for your efforts.