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