i'll bite i cant scan something here at home so will describe and see if it is sufficient?
from radio shack or digikey or newark etc.... one complete kit for each output; either 2 or 4 would/shud be sufficient.... full wave bridge rectifier rated 100ma, 100v to resistor to led each. thats it.
fw bridge ac input terminals across each coil. dc +&- out of it to LED in series with the resistor. resistor size depends on ur stepper dc power supply voltage (Vsuppy-2v))/.03a for ohms rating. shud be nice for the kids to see.
this would get u started. u may need to add another resistor and zener diode to the LED side of fw bridge to make led consistent at all speeds...... but that can wait until after u get initial circuit up and running. if no lite first time thru, reverse led polarity.