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