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