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