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)(11,17)(12,14)(13,16)(15,18)(19,23)(20,21)(22,24)(25,26,32,36)(27,37,38,33)(28,34,29,39)(30,31,35,40)(1,2)(3,5)(4,6)(7,8)(9,10,14,12)(11,15,18,17)(13,20,21,16)(19,23,24,22)(25,27,32,38)(26,33,36,37)(28,35,29,30)(31,39,40,34)(1,3,4,7)(2,5,6,8)(10,12)(11,18)(16,20)(19,24)(25,28,32,29)(26,34,36,39)(27,30,38,35)(31,33,40,37)(9,11)(10,15)(12,17)(13,19)(14,18)(16,22)(20,23)(21,24)(25,29,32,28)(26,34,36,39)(27,30,38,35)(31,37,40,33)(9,12,14,10)(11,17,18,15)(13,16,21,20)(19,22,24,23)(25,30)(26,31)(27,28)(29,38)(32,35)(33,39)(34,37)(36,40)(9,13)(10,16)(11,19)(12,20)(14,21)(15,22)(17,23)(18,24)(25,31)(26,35)(27,34)(28,33)(29,37)(30,36)(32,40)(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.