I'm not too good in graphviz, but the way I can do is starting out my drawings with dotty.
The dotty user guide can be found at https://www.graphviz.org/pdf/dottyguide.pdf.
See chapter 2.1 of it, that's pretty much all that i've been
reading of it so far.
Switch layout engines between the likes by "set graph attr" in
dotty and "layout=dot" or "layout=neato" or "layout=circo" or
"layout=fdp" etc. See "man 7 graphviz" for the list, and for the
layout-specific parameters.
For basic layouts, you will only need to:
I'm not sure how to run dotty in a way such so as to the graph
having an associated .dot
file, but
probably placing it as the argument to dotty command. If it
doesn't have it associated, "save graph as" nor "load graph" won't
create the association seemingly, and thus the "save graph"
(without the "as") nor "reload graph" right-click-menu commands
will do seemingly nothing.