You will need to adjust the post type definition to have a distinct "capability type" (or define each post-related capability uniquely). Then add the corresponding capabilities to each desired WordPress role definition.
Capability Manager Enhanced assists this task in a couple ways:
- Press Permit users can automate the definition of post type capabilities a simple enable/disable switch for each post type in the CM sidebar.
Once the post type capabilities are defined, a row of post capability checkboxes become available on the CM role editing screen.