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