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