While we wait for an actual film or TV adaptation of Illuminatus!, there is a website called This Movie Does Not Exist that uses artificial intelligence to make posters for nonexistent movies. You can make three free movie posters, then you have to pay, so I made three Illuminatus! posters. The one above is one that I thought wasn't terrible. (Here is one of the rejects). If you give it a try, please post the link in the comments.