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