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