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