No ! please do not connect a digital output directly to a pin of a 3.3V sensor.
When you do digitalWrite( pin, HIGH); then that pin outputs 5V up to 40mA. You may not push that into the AD0 pin of the 3.3V sensor.
Even connecting SDA and SCL from the Mega board directly to the sensor is not safe, since the Mega board has onboard pullup resistors of 10k to 5V.
You have to use level shifters for all the signals, or buy a 3.3V Arduino board.