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)(27,34)(28,29)(30,31)(32,37)(33,38)(35,40)(36,39) 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)(26,31)(28,33)(32,34)(35,39) involution — undirected(2,5)(6,7)(10,14)(11,18)(16,20)(19,24)(25,26,30,31)(27,32,37,34)(28,29,33,38)(35,36,39,40)(1,2)(3,6)(4,5)(7,8)(9,10)(11,15)(12,16)(13,14)(17,18)(19,22)(20,21)(23,24)(25,27,30,37)(26,32,31,34)(28,35,33,39)(29,36,38,40)(1,2)(3,6)(4,5)(7,8)(9,11,13,18)(10,15,14,17)(12,19,21,24)(16,22,20,23)(25,28,30,33)(26,29,31,38)(27,35,37,39)(32,36,34,40)(1,3)(2,6)(4,8)(5,7)(9,12,13,21)(10,16,14,20)(11,19,18,24)(15,22,17,23)(25,29)(26,33)(27,36)(28,31)(30,38)(32,39)(34,35)(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.