You can change the name of a diagram’s title easily by editing the draw.io macro in your Confluence Data Center or Server page.

1. Edit the Confluence page, click on the macro of the draw.io diagram you want to rename, then click Edit Macro.
   
2. Enter a new Diagram Title, set the Toolbar dropdown to Top so the title is displayed in view mode, then click Save.
   
3. Save and publish your Confluence page.

Hover over the diagram to see its title and version number above the diagram when you view the Confluence page.

Change the filenames of the attachments

If you want to change the filenames of the attached diagram files on your Confluence page, is more difficult as Atlassian does not easily allow you to rename attachments that are used within macros.

See how to manually change the filenames of the the two draw.io attachment files