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