Not surprised you'd couldn't find one - it's well hidden!
It's part of the fuel pump. In order to get at it you need to remove the fuel pump, then push in the tabs and prize apart the outer casing (that forms the mounting plate) to expose the end of pump itself. On the bottom of the pump you'll find a pillow-shaped gauze sack, which is the filter...
If you disassemble the pump, don't break anything - there �700 new!!