You've drawn a parallel resonant circuit which presents a low impedance except at resonance - and only allows twice the supply volts across the piezo.
A series resonant circuit becomes low impedance at resonance, and forces a lot of current to flow through the piezo. It has no such limitation .
If you used my circuit with a 56mH and added a 2.2nF across the piezo you'd also acheive resonance, and it ought to work at about 4.6 kHz
Note you can't use a single transistor driver here - try an arduino output to start with and tweak the extra C for best output.