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