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