That said, I really, really appreciate when I can see a tangible piece of code that solves a real problem. In the case of concurrency, perhaps a hello world from an actor, ping pong, a chat room, cancellation, timeout or similar. Show something that's easy to do in this model, which is tedious to do in different models. (This shouldn't be hard to find, since concurrency is ridiculously easy to get wrong in most languages).
If a partial goal is to engage practicians, then code samples is very effective. I usually don't need the full theory to grok code even in a foreign paradigm. If I can get an initial sense and I like it, then I am infinitely more willing to read up on the theory. Now, unfortunately, you're missing out on one very curious, albeit lazy, reader.
For the record, the closest I could find was some pseudo-code[1]. If there's more please share!
[1]: https://synit.org/book/syndicated-actor-model.html
EDIT: I'm stupid, there are a couple of examples on the linked page if you scroll down. I wish there were more!