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