One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(8,12)(10,11)(13,14)(15,19)(16,20)(17,18) involution — undirected(1,2)(3,4)(5,6)(7,9)(8,10)(11,12) involution — undirected(6,7)(10,11)(14,18)(15,20) involution — undirected(13,15,17,20)(14,19,18,16)(5,7,9,6)(8,11,12,10)(13,16,17,19)(14,20,18,15)(5,8)(6,10)(7,11)(9,12) involution — undirectedA 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.