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