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