In Confluence, the draw.io Simple Viewer prevents all interaction and hides the diagram toolbar when viewing a diagram on a Confluence page. Instead of an interactive diagram, it displays a simple PNG image - you can’t click on links, step through pages or enable/disable layers.

To turn this Simple Viewer off and allow users to interact with the draw.io diagram when reading a Confluence page, you need to edit the draw.io diagram.

1. Edit the Confluence page.
2. Edit the draw.io diagram that is currently using the simple viewer.
3. In the draw.io editor, make sure nothing in your diagram is selected, then deselect Simple Viewer from the Diagram tab in the panel on the right.
   
4. Save the diagram, and publish the Confluence page to save your changes.