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