Hey Ryan,
You should be able to see related Module as in this case.
I have tested this in 7612. Patch Info-
It has to be investigated why No Option is coming but meanwhile to cancel the related Contract for this record , go to database and fire this query which will give you all related contracts which you can cancel first before cancelling Master Contract.
SELECT * FROM maximo.CONTRACT c WHERE orgid = <ORGID of Master Contract Record> and masternum='<Your Master Contract Number>'