Answer
The graph is shown below.
Work Step by Step
The given equation of the line is
$x=3$
This is the standard form x=k. it is a vertical line whose $x-$ intercept is k.
We have $k=3$
The points on the line are $(3,1),(3,2)$ and $(3,3)$ and so on.
Take two such points - for example $(3,1)$ and $(3,2)$ - and draw a line. Take a checkpoint, for example $(3,3)$ and notice it belongs to the line.