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