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