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