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