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