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