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