The negative of a polarized capacitor is going to be connected to ground. So the capacitor on the right is connected to the positive (red) and negative / GND (black) rails of the breadboard.
The one of the left shares the GND pin of the regulator which looks to be the middle pin. So the cap on the left will connect across the VIN and GND of the regulator.
I would also suggest adding a .1uF ceramic capacitor on the output pin to GND. This will sometimes prevent high frequency oscillation on the output voltage. It is reccommended on the spec sheets. I have only seen the oscillation once, but it caused me grief not having it, so I now just add it.