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