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