I looked up the specs on this device at _
http://www.sharpinbusiness.co.uk_. It would appear that this device has optional general printer options. That is, it may not understand any printer language at all.
You may be able to use a generic PCL 5e or PCL 6 driver. Those would be the most likely of any printer languages to be supported. You may already have the Gutenprint drivers installed on your computer. They are part of the default installation of OS X. The generic PCL Gutenprint drivers only support grayscale printing, but it should give you an idea of whether this will work for you.
Let us know if you can get output from the Gutenprint drivers. There are other drivers that will allow you to add color support that we could explore.
Matt