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