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