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