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