Where to find z coordinate in G-code for delta printer
It isn't hidden at all. It's just that the Z-axis position only changes with each layer change, so the Z coordinate is only passed at layer change. On line 17 of your example G-code, it starts the first layer at Z=0.5mm:

G1 Z0.500 F7800.000


The next time you should expect Z to appear is on the next layer.