LinkedDataHub looks cool enough for non-tech users, but I prefer working inside a repl/Slime/etc. interactive programming environment.
Also, Google, Facebook, most banks, etc., etc., use Knowledge Graphs - pretty solid technology.
The enterprise Knowledge Graphs (yes, it's the same SemWeb tech stack in principle) in Fortune 500 sized companies have in-house platforms that present the graph to the end-users, with entity browsers, analytics, dashboards, structured content etc. LinkedDataHub is an attempt to bootstrap an open-source, standards-driven version of that.
https://github.com/paulhoule/gastrodon
Overall I think of graph visualization as a problem, in particularly there are some people who just don't see that hairballs are incomprehensible
Statistical summary plots are more useful.
Maybe one day someone will figure something out, but much like scatter plots fall over when you plot vast amounts of raw data, so do plotting graphs.
I went to an exhibit of this guy's works
https://en.wikipedia.org/wiki/Mark_Lombardi
and saw a series of drafts he'd made where he had drawn many different versions of a conspiracy social network and gradually went from a hairball to something that looked meaningful.
In terms of turning this into a tool there's the interesting problem that there is a graph that comes in from the outside world (and could be regenerated) and also data that represents the curation of the graph (Do I show this? What color is this line? What position does this node get displayed at?) You've got to be able to edit one independently of the other and deal with things sometimes getting out of sync to have a tool that advances over the state of the art.