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