Ask HN: Presenting Software Engineering as a Career to HS Students?

A brief background: I'm a Senior Software Engineer for a large company. I've been in the industry for 5 1/2 years and been out of high school for 9 years. I recently got asked to give a presentation at my alma mater during their Career Day next week. This is a small high school (maybe 150 students total for grades 9-12) and I'm 99% sure that they do not offer any programming classes. They certainly didn't when I was there. So I'm guessing a majority of the students don't have any programming experience at all.

I just wanted to see if anyone had any ideas on how best to 'sell' computer science to these students? I actually participated in their Career Day two years ago but I just found the old Keynote I gave and I'm not that impressed. I think I can do better. It's a 30 minute timeslot (leaving maybe 5-10 minutes for questions). Anyone have any ideas for how to approach a presentation like this?

Thank you!