The manufacturer should have provided this info for you. From Xilinx, I do not think there was any standard pinout. Most of the cables directly from Xilinx can with flying leads rather than a set pinout. With their individual leads, you could bundle them into any pinout you wanted.
This typically how the interface is done. Since Xilinx sets the pinout on the parallel port, you can easily determine which parallel port pin drives which JTAG line from the schematic. Then by comparing it to your device, you can determine their pinout.