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