I agree with Erik. I created such diagrams and they can only serve as an overview of the tables.
I have created E/R diagrams for Navision 4.0 (http://navitools.com).
...and NAV 2016: https://dynamicsdocs.com
Alternative is to create a dynamic version of the diagrams with fewer tables on each diagram and links to detailed information about the tables. I did something similar for Odoo (http://useopenerp.com).