The coil polarity in that diagram is reversed. "+" on coil should go to the positive supply.
There is no protection for the transistor against high voltage spikes.
Old style ignition coils are better for these types of projects.
They have lower primary coil current because they were designed to work with distributor contact points.
The newer coils draw more current because they are switched by an electronic circuit.
I made a spark generator years ago using a HA12 Lucas coil and a five terminal changeover mini relay.
It was used to test distributor caps and rotors for tracking.