This example code generates a random graph.
\documentclass[tikz,border=5mm]{standalone}\begin{document}\begin{tikzpicture}\foreach \i in {0,1,...,19}{\foreach \j in {1,2,3}{\pgfmathsetmacro{\thenum}{int(random(0,19))}\draw (18*\i:3) -- (18*\thenum:3);}}\foreach \i in {0,1,...,19}{\filldraw [fill=white,draw=black] (18*\i:3) circle(2pt);}\end{tikzpicture}\end{document}
By S. Bau; Sat Sep 24 2022; gengchen