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