There are tools that you can use to hide members of a class. I think Rational System Architect supports this and surely Sparx Enterprise Architect does. With such a tool I would create two diagrams, one displaying the members only (and a collapsed methods part) and one displaying the methods only (and a collapsed members part). Something like:
+--------------------+
| SomeClass |
+--------------------+
| methods |
+--------------------+
| +DateOfBirth: Date |
| +Name : String |
| … |
+--------------------+
+----------------------------+
| SomeClass |
+----------------------------+
| members |
+----------------------------+
| +void Say(String message) |
| +void Sleep(TimeSpan time) |
| … |
+----------------------------+
If you want to be sure the readers of the documents understand the meaning of your diagrams you could drop a line explaining why you hid parts of the class.