How can I create an ERD from an existing database in Microsoft SQL Server 2014?
The ERD needs to resemble:
The easiest way to do so, would be from SQL Server Management Studio (SSMS).
Go to Database -> Database Diagrams -> Right click -> Add new diagram -> Add the desired tables for your ERD. Given your tables actually have relationships defined between them the relationships will be drawn as well.
It should be noted, this will be a very basic looking ERD, and might not be quite to the standard of what you would expect out of an ERD.