Universe saves your Graph every 60 seconds automatically (saving is not performed if mouse is not being moved around), and also when you close the Graph or press Play. Apart from auto save, you can also save your Graph manually via Save button. The system stores 30 last saved versions of each Graph.
To restore last graph state, open "Backups" foldout in VizioComponent and choose a restore point. You can preview the selected state by clicking on a button with time indication and restore your graph by clicking on "Restore" button. It's easy.