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