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