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