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