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