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