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