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