For this you require one more software application MS office Visio 2007/2010.
Step to follow:
1. You have to create a project by taking the objects in which you want to see UML/ER diagram.
2. Then click reverse Engineer button.
3. Select the location and the diagram type and the project type and click ok.
4. If you select the UML diagram then it will create a .vsd format file.
5. It will call directly the Visio application and create the UML structure.
6. Under Model Explorer we can find the Static Model >Top Package>Project name.
7. You can drag and drop to the blank page and it will create diagram based on the relationship.
8. If you select the ER model then it will create a .ERX format file.
9. To read that file you have to go to the visio application.
10. Click File > New > Software and Database (or Database if you are using Microsoft Office Visio) > Database Model Diagram.
11. On the Database menu, point to Import, and then click Import Erwin ERX file.
12. In the dialog box, click the Browse button, navigate to the location of the .erx file that you generated from the Reverse Engineering tool, select the file, and then click OK.
13. On the Database menu, point to View, and then click Tables and Views.
14. Drag items from the Table and Views window onto the diagram surface.
15. After you have added a table to the diagram, you can right-click the table in the diagram, and then click Show Related Tables. This will add all the related tables from the Tables and Views window that

http://www.blueink.biz/DataModelingVisio.aspx
http://en.wikipedia.org/wiki/Cardinality_(data_modeling)
http://www.blurtit.com/q775064.html
http://www.nearinfinity.com/blogs/lee_richardson/an_entity_relationship_diagram_example.html