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