Improving Drawing Performance for big Graphs

[BauePhil]

I currently face the issue of improving the performance of a Zest Graph with lots of nodes (~12000) and connections (~75000). Big Graphs like this become an issue when fully zoomed out and everything is painted (zoomed in it's ok as only the visible items are painted I believe). I understand that multithreading the drawing process is not allowed (also tried that as I didn't know that previously), is there maybe a way to cache figures as images, or any other way to improve the drawing performance?
FYI: checked with VisualVM and the primary contributors to runtime are the SWT draw (drawLine, drawPath, drawOval, ...) methods.