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