The keyboard should work without any special drivers. The MacOS has generic USB drivers built into it that enable it to use most input devices (on a basic level, advanced features like multi-button mice or specific keyboards functions won't be available) that rely on USB.
You'll be missing the Command, Option and Control buttons (having never seen an SGI keyboard tho', it may have some buttons that would be "mapped" by the OS to those specific keys) and you may encounter some other oddities. But it should work as a functional keyboard for the basics (like typing, etc.).