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