This sent me down a rabbit hole since it's something I've half-considering for a while. I prefer text configuration rather than GUI so I ended up installing graph-easy on my debian laptop:

sudo apt install libgraph-easy-perl

and made a first attempt to diagram the power setup in my campervan

It's a perl module but the graph-easy wrapper makes it behave like any other CLI tool. cat or echo the config text to the wrapper and the graph pops out on STDOUT