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