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