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)(28,38)(29,34)(30,31)(32,35)(36,39)(37,40)(1,2,5,4)(3,7,8,6)(10,14)(15,17)(16,21)(22,23)(25,27,32,30)(26,33,35,31)(28,37,29,36)(34,39,38,40)(1,3,5,8)(2,6,4,7)(9,10)(11,15)(12,16)(13,14)(17,19)(18,22)(20,21)(23,24)(25,28,32,29)(26,34,35,38)(27,36,30,37)(31,39,33,40)(1,4,5,2)(3,7,8,6)(9,10)(11,15)(12,16)(13,14)(17,19)(18,22)(20,21)(23,24)(25,29,32,28)(26,34,35,38)(27,37,30,36)(31,39,33,40)(9,11,13,19)(10,15,14,17)(12,18,20,24)(16,22,21,23)(25,30,32,27)(26,33,35,31)(28,37,29,36)(34,40,38,39)(9,12,13,20)(10,16,14,21)(11,18,19,24)(15,22,17,23)(25,31,32,33)(26,30,35,27)(28,39,29,40)(34,37,38,36)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.