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