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