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