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