SmartDraw includes thousands of professional-looking diagrams like this that you can easily edit and make your own.
Text in this example:
High value
(Very important) Low Value
(Not as important) Deadline
(High urgency) 1. Do it now! 3. Gotta minute? No Deadline
(Low urgency) 2. I really should... 4. I really shouldn't Time/Value Matrix: Prioritizing your activities