You want the relay to drive the LED? Latching the relay is pretty easy using two push buttons. One normally open and one normally closed. If you just want a single button then a flip flop chip would figure into things. If the LED is just an everyday low current (10 - 15 mA LED) then it can be done using just a flip flop.
<EDIT> The Takamisawa AL5WNK is a latching relay with a 5 Volt coil and two change-over contacts (DPDT, Double Pole Double Throw).
As a latching relay, the relay will "memorize" its state even after power is removed. Reversing polarity puts the relay in the opposite state.
That is the relay you have so what exactly are you trying to do? </EDIT>
Ron