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