@flohit Are you referring to GraphViz? I'm not sure if you are asking how to use it, or if you are just curious about how I use it specifically. To learn the syntax just look at the usage and readme tabs on the plugin page.
@Soren Its been a while since I tried it, but IIR there was a bug where graphs would randomly get rendered at the bottom of the screen, outside of any tiddler. I can't remember more detail than that though. Thanks for sharing your fix for the text-cut-off bug, and maybe I will try out one of the updated forks at some point.