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