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