https://github.com/vizdom-dev/vizdom/ seems like a nice library for rendering directed graphs into SVG, and apparently has automatic layout capabilities.
So far it has automatic layout that will position (and create a rendering) for hierarchical graphs - even if your data isn't hierarchical in nature. This is how the algorithm works internally as it is a reflection of Dagrejs.
I plan to support more layout types in the future.
As for placement of 'root' nodes (aka source and sink nodes) - in reference to the parent comment - my hope is to expose graph theory methods that you can run before layout/render which would help facilitate this automatically, but it's non-trivial to codify as it requires a substantial refactor to the layout algorithm(s).
Please note that while Vizdom is freely available for use under the Apache License 2.0, the Rust WebAssembly binary included in this library is closed-source. You are free to use the library, but the source code for the Rust WebAssembly binary is not publicly available.
