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