One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,5)(3,6,7,8)(9,10,13,16)(11,17,18,14)(12,15,20,22)(19,23,24,21)(25,26,31,39,29,33,30,34)(27,32,40,37,35,28,36,38)(2,5)(6,8)(9,11)(10,14)(12,19)(13,18)(15,21)(16,17)(20,24)(22,23)(25,27)(26,28)(29,35)(30,36)(31,40)(32,33)(34,37)(38,39) involution — undirected(11,18)(14,17)(19,24)(21,23)(25,28,29,32)(26,27,33,35)(30,38,31,37)(34,40,39,36)(1,3,4,7)(2,6,5,8)(12,20)(15,22)(19,24)(21,23)(25,27)(26,32)(28,33)(29,35)(30,36)(31,40)(34,38)(37,39)(9,12,13,20)(10,15,16,22)(11,19,18,24)(14,21,17,23)(26,33)(27,35)(34,39)(36,40)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.