Is there a way to generate a simple dependenices graph for a given target, when I run

./pants dependencies --transitive path/to/thing

i get a flat list. I am wondering if Pants can show a graph of the dependencies, both within the Repo, but also the 3rd party ones.

Not easily, and not including transitive 3rd party deps at all, just direct 3rd party deps. You use the json from the

./pants peek

goal to cobble together what you want. Toolchain has done that here with the output being a fairly fancy webapp / ui, but you could also transform the json into local textual output too: https://graphmyrepo.com/app/repo/pantsbuild/pants