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