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