draw a dotted vertical line at x=-3
shad everthing to the right of that dotted line
it's dotted to indicate the solution does not include the line itself
criss cross type shading is one method or darken, blacken the entire area to the right of the dotted line
also sometimes put a few arrows pointing right, at the top bottom and right side of the shaded area , to indicate the shaded area goes forever
that's a 2 dimensional graph
a one dimensional graph would be to draw an open small circle on the real number line at x=-3 and draw a line to the right of that point, with an arrow at the end to indicate the line goes forever.
that's about all anyone ever does, although theoretically, you could graph x>-3 in 3 dimensions, but drawing 3 D in 2D is a little tricky.
