One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,8)(9,10)(11,12)(13,14)(15,19)(16,17)(18,20) involution — undirected(10,12)(13,14)(15,18)(16,17)(19,20) involution — undirected(6,8)(10,12)(14,17)(18,19) involution — undirected(1,2)(3,4)(5,6)(7,8)(9,10)(11,12)(13,14)(15,18)(16,17)(19,20) involution — undirected(13,15,16,20)(14,18,17,19)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.