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