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