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