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