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