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