They've had an Electron version out for at least a year now. I use it every day on Ubuntu.

https://github.com/jgraph/drawio-desktop

That can't be right, I use draw.io on my mint laptop, from https://github.com/jgraph/drawio-desktop/releases

There's a VS Code extension to view and edit them. Perhaps that works on Linux?

https://github.com/hediet/vscode-drawio