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