Yes, an ORM tool such as NORMA can map ORM schemas to relational schemas, although currently some of the more advanced constraints are not mapped. If you are using NORMA, just right-click an empty space in the Document Window, select Extension Manager from the context-menu, click Relational View and press OK to see a diagram of the relational schema that is automatically generated.
For further details on using NORMA to perform a relational map, see the NORMA labs that are accessible at either www.ORMFoundation.org or www.orm.net. For more detailed coverage, see my latest book 'Object-Role Modeling Fundamentals' (there is a link on my website to purchase that book ).
Cheers
Terry