Most of the time, I used Microsoft Visio to draw all the diagrams. Whether it is UML, flow chart, use case, database, Visio is the standard tool for me. Quite often, I had to come up with the database design and always looking for a tool to connect with SQL Server/SQL Azure. The tool should prepare the model for me to review and make any required changes. Needless to say, Visio has the feature. Using Visio database model explorer, you can connect to the database to bring up the model and send the modification back to the database.
Here is the link to download the Data Model Explorer and get started with the reverse engineering feature.