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