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