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