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