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)(11,14)(12,15)(13,16)(17,19)(18,21)(20,22)(23,24)(25,26,31,32)(27,36,37,33)(28,40,34,29)(30,35,38,39)(3,7)(5,8)(9,10,13,16)(11,17,19,14)(12,15,20,22)(18,23,24,21)(26,32)(27,37)(28,34)(35,39)(1,2)(3,5)(4,6)(7,8)(12,20)(15,22)(18,24)(21,23)(25,27)(26,33)(28,38)(29,39)(30,34)(31,37)(32,36)(35,40) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,10)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,28,31,34)(26,29,32,40)(27,38,37,30)(33,39,36,35)(1,2)(3,5)(4,6)(7,8)(9,11,13,19)(10,14,16,17)(12,18,20,24)(15,21,22,23)(25,29)(26,34)(27,39)(28,32)(30,33)(31,40)(35,37)(36,38)(9,12,13,20)(10,15,16,22)(11,18,19,24)(14,21,17,23)(25,30,31,38)(26,35,32,39)(27,34,37,28)(29,33,40,36)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.