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