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