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