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