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