Difference between driver and transistor
It is a "Line" driver, as in to drive a bus with many other ICs that the previous part of the circuit can't drive. 

It has:


clear I/O Low/High voltage levels,
low current requirement for input, (with a transistor you need a base current) 
clear propagation delay and push-pull output, (with a single transistor you have open collector or emitter)
enable pin, so you can have many different drivers drive the same lines (i.e. 64 outputs and 8 inputs, then you enable one driver at a time)
etc


So its a "driver" for specific purposes on circuits, not a generic driver for LEDs. (There are darlington arrays for example that are made to drive loads, see ULN200X for example).

In essence you are kind of looking at the wrong part for the job.