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