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