THERE ARE A NUMBER OF DIAGRAM MAKING SOFTWARE AVAILABLE IN PUBLIC DOMAIN. PLEASE SELECT ONE THAT YOU PREFER.
Here are some:

https://www.microsoft.com/en-us/download/confirmation.aspx?id=53055 (Links to an external site.)
Download Update for Microsoft Visio 2016 (KB3115298) 64-Bit Edition from Official Microsoft Download Center (Links to an external site.)
Microsoft has released an update for Microsoft Visio 2016 64-Bit Edition. This update provides the latest fixes to Microsoft Visio 2016 64-Bit Edition. Additionally, this update contains stability and performance improvements.

www.microsoft.com

http://staruml.io/ (Links to an external site.)
StarUML (Links to an external site.)
UML 2. Compatible with UML 2.x standard metamodel and diagrams: Class, Object, Use Case, Component, Deployment, Composite Structure, Sequence, Communication …