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