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