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