There isn't one on the back panel. You must connect the USB/1394 bracket that's included with the board to an empty slot on the rear of the computer and hook up its connectors INSIDE the computer to the appropriate headers on the motherboard: the
purple firewire connector would connect to the
purple header (DUH!) on the RIGHT in the pic below, it's a DOUBLE firewire header and it's the only place this bracket will fit. The yellow USB connector would go to any open USB header on the board (guess what color...) Very simple, really.
Optionally if your computer case has a built-in firewire port on the FRONT panel, as most do nowadays, you can connect that to the appropriate header on the board using the already-installed cable that's connected to that front firewire port (connect this one to the purple header on the LEFT, it's just a SINGLE firewire port.)
However, this header's pins will NOT match up properly with almost all case's front-panel firewire connectors. You would most likely have to switch around 2 or 3 of the little wires that go into the connector so that it matches the motherboard's pin-out.
It's clearly labled in the manual for the board, and isn't really all that difficult to switch the wires around, but I would recommend just going with the first option and connect the included bracket to the back since it was designed to go with this board and requires no modification.