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