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