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