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