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