In your circuit, no needs to add any diode, because the Led is already like diode.This is what I have so far as a circuit diagram:
View attachment 113211
Would your addition to my circuit work if it was applied to each output of the 4017 after the 2N7000 diode?
And you just add 7 circuits that I drew on #34 to the output of CD4017, which mosfet is properly for your application, the first is that you should know the resistance of copper coil and calculate the draw current, to avoid the mosfet turn on and latch, so you should add the Rgs(R1).
If you want to add the led to the circuit then you can using each led in series with a resistor and in parallel with the copper coil.