the best tool for you design diagram which there are as below:

1. draw.io
   draw.io is an open source technology stack for building diagramming applications, and the world’s most widely used browser-based end-user diagramming software.
   For me, I recommend you to use this tool because It’s easy export and share to our drive.
   

2.  Lucidchart
   Lucidchart is the intelligent diagramming application that brings teams together to make better decisions and build the future.
   

3. Excalidraw
   Excalidraw is a whiteboard tool that lets you easily sketch .
   

4.  tldraw
   tldraw is a tiny little drawing app.
   

5. edrawsoft.com
   Plan, visualize, and present better results — all in EdrawMax. Get started easily with the Microsoft-like interface, drag and drop feature, and professional template resources. With 280 types of diagram solutions, you and your team can use EdrawMax for every stage of your workflow.
   

6. Miro
   Miro Lite is a free-to-use, easy-to-share online whiteboard.
   

7. CloudSkew
   CloudSkew is an online diagram & flowchart editor.