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