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