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