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