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