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