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