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