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)(25,26,31,38,30,34,29,33)(27,35,28,32,36,40,37,39)(1,3)(2,5)(4,8)(6,7)(9,11)(10,14)(12,19)(13,18)(15,23)(16,22)(17,20)(21,24)(25,27,30,36)(26,32,34,39)(28,31,37,29)(33,40,38,35)(2,6)(5,7)(9,12,13,20)(10,15,16,24)(11,17,18,19)(14,21,22,23)(27,36)(28,37)(32,39)(35,40)(3,8)(5,7)(12,20)(15,24)(17,19)(21,23)(25,28,29,27,30,37,31,36)(26,32,33,35,34,39,38,40)(10,16)(11,18)(15,24)(17,19)(25,29,30,31)(26,33,34,38)(27,37,36,28)(32,35,39,40)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.