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