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