Which diagram is better for common mode noise rejection?
The second diagram is better because the differential inputs don't share a wire with the power supply feed providing 0 volts to the sensor. That 0 volt feed will take current and, in the simple DC scenario will cause a volt drop that is an unknown value - that DC volt drop adds to the signal measured: -



X = unknown volt drop.

Your second diagram is better because the unknown volt drop (x) is disregarded by the differential amplifier.