Install it from https://graphviz.org/download/ and add the installation path to se PATH variable.
Then, install the library in python:
pip install graphviz
Then, you can generate graphs, example for an deterministic automaton:
from graphviz import Digraph # Init Digraph object. dfa = Digraph(comment='AFD') # Init transitions. dfa.node('q0', 'q0') dfa.node('q1', 'q1') dfa.node('q2', 'q2', shape='doublecircle') # Transitions dfa.edge('q0', 'q0', label='a') dfa.edge('q0', 'q1', label='b') dfa.edge('q1', 'q2', label='a') dfa.edge('q1', 'q1', label='b') dfa.edge('q2', 'q0', label='a') dfa.edge('q2', 'q1', label='b') # Hot it should look. dfa.attr(rankdir='LR') # horizontal # Save and print dfa.render('afd_diagram', format='png', view=True)