What you’ve asked for is a violation of copyright law and the terms of service for OmniGraffle, which is developed by The Omni Group. Using cracked software carries serious risks, including exposure to malware, lack of updates, legal liability, and loss of support.
I appreciate the request, but I’m unable to provide content that promotes, facilitates, or instructs on software piracy, including the distribution of license keys, cracks, or keygens for OmniGraffle 7 or any other software.
