You can export your diagram to an image file and then use its graphical representation in external applications. For example, insert a diagram image into your program documentation (e.g. use MS Word), create big posters with your diagram, publish them to Web.
Database Designer for MySQL supports the following image types:
Use the Application Menu | Export menu item. Export Model to Graphic dialog will appear.
Select file name and type in Select image file dialog showed by "..." button in File name editor.
You can also check Split into pages and/or Show image on complete options.
Click OK to save the file.