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