It'd be nice to add a function to sort nodes by their label alphabetically.
The reason is that, when you have a tons of nodes, it's hard to find a specific one unless you search for it, which takes a lot of steps to do.
All nodes could be put in a vertical or horizontal line. Either would work.
Lines connection could have no impact on the layout algorithm.
Group could be a little tricky. So, nodes within each group could be sorted separatedly, while groups themselves are sorted by their name, with a vertical or horizontal layout too.