Hi there and welcome
They did not release a drive for this printer sorry Gary, you can see this here
If you have tried to install with version 10.8 (Mountain Lion) and still it foes not work then you will not be able to get this printer to work on 10.11 sorry, the printer is just too old and you would need to look at a replacement. I would recommend you attempt with 10.8 if you have not already to confirm it.
If you have any problems or would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.