Each TLC device will control a row of LEDs. Eight devices will control 8 rows, that's 1 layer. All the anodes from 1 layer will have current sourced from 1 PNP, or P-channel, device.
All the LEDs in a column get their cathodes connected in parallel, to a single TLC pin.
Send out TLC data for 1 layer, enable that layer's current source.
Repeat the next layer.
Thanks. Having the drain connected to 3.3V, source to the TLC5951 pin, and switching the gate between GND and 3.3V has no effect (LED is always on).