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