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