Drain the rice and steam in a sticky rice steamer or on the stove top.
Put 3 tablespoons of the coconut milk into a small saucepan and cook until hot. Set aside.
In a bowl mix the remaining coconut milk, sugar and salt until the sugar and salt are dissolved. Add the cooked sticky rice and fold the coconut milk in until mixed well. Let the rice stand covered for about 15 minutes.
Meanwhile, cut the mango off the pits and skin. Slice the mango into strips and place on a platter.
When the rice is finished resting, scoop the rice onto the platter next to the mango.
Sprinkle the rice with the toasted sesame seeds and 3 tablespoons cooked coconut milk. Serve.