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