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