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