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