Hello, Codeforces!
Check the graph preview tool — Graph Editor
Uses Simulated Annealing algorithm; Shows good results on planar and almost planar graphs.
Features:
easy input copy/paste;
random graph generator;
highlighting adjacent vertices on hover;
save as png.
Please leave your feedback and links to similar tools in the comments below.
At the moment I know about these:
CS Academy Graph Editor
miska924 DrawGraphJS: Try here; or Check github page