Quite legal, but very non-rectangular. Lots of very wide nodes plus wide-ish edge labels. Some suggestions:
- change to rankdir=TB. Yes it changes the look, but this is the easiest way to have a very large impact. (Note that some of the edges may be less attractive (wavy)).
- if possible, add more newlines to the node labels (to reduce label width). If you are brave, you might look at this: Text wrapping in Graphviz? - #4 by ronman
- alternatively, consider structuring the label text into record or html format to reduce label width (Node Shapes | Graphviz)
- use the unflatten program (https://graphviz.org/pdf/unflatten.1.pdf) to try to make the graph more rectangular
- reduce fontsize (simple, but not a huge impact)