The rules for citing a graph are the same for citing a photo, illustration, map, or diagram. Place the image in the body of the essay where it is pertinent to the subject matter, and give the citation after labeling it with "Fig." and a number. Use the numbers consecutively from 1 on.
Fig. 1. Party agree graph from: McCready, Ryan. "5 Ways Writers Use Misleading Graphs To Manipulate You [INFOGRAPHIC]." Venngage, 9 Sep 2018.
The citation should be double spaced and the only difference should be the notation "Fig." and the number which should be bold with periods after the notation and number as shown here.