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