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