PowerDesigner is a tool used by many data architects. CaseTalk strengthens them in using language and well documented entities and tables. Yet, if your goal is simply to draw an relational diagram, you should perhaps consider replacing that with the CaseTalk Viewer.
Below you'll see the different outputs generated by CaseTalk and PowerDesigner.
Modeler
With CaseTalk Modeler your fact based models can already be displayed in full customizable details.
CDM
In PowerDesigner the Conceptual Model is build using a VB Script generated by CaseTalk Modeler, depicting a transformed fact based model.
PDM
In PowerDesigner the Physical Model is build using a VB Script generated by CaseTalk Modeler, depicting a transformed fact based model.
Entity Details
In PowerDesigner the Entities and Tables are well documented using business language and examples, coming from CaseTalk's fact based models.
Viewer
A similar relational model can be shown by simple drag and drop operations in the free CaseTalk Viewer.If all you care about is diagramming it certainly rivals with PowerDesigner. For physical design and database editing, you should remain using PowerDesigner and feed the initial models with CaseTalk scripts.