The domain is the values of the relation, and the range is the resulting values of each of the values in the domain for the relation (roughly speaking).
We need to find any pair of values in the graph to answer this question. Then (from left to right):
(-1, 3), (-1, -3), (3, -1)
Then, the domain is:
{-1, 3}
The range is:
{-3, -1, 3}