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