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