I'm a big fan of both Mermaid and Graphviz - Thanks to GitLab supporting Mermaid we can put relevant project diagrams inline in Markdown docs that live in the same git repo as the rest of the project code.

And if I need to generate a graph programmaticaly then I instinctively reach for Graphviz as it's solid and can produce the graphs in so many different file formats that they're easy to include wherever they're needed. Your code is a lot simpler as it doesn't need to handle any of the rendering logic, it just needs to work out which nodes are connected by which edges.