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)(11,14)(12,16)(13,17)(15,18)(19,22)(20,21)(23,24)(25,26,29,30)(27,31,34,37)(28,32,35,38)(33,39,36,40)(1,3,5,8)(2,6,4,7)(9,11)(10,14)(12,19)(13,18)(15,17)(16,22)(20,23)(21,24)(25,26)(27,31)(28,32)(29,30)(33,39)(34,37)(35,38)(36,40)(11,18)(14,15)(19,24)(22,23)(26,30)(28,35)(31,37)(33,36) involution — undirected(1,2,5,4)(3,6,8,7)(9,10)(11,14)(12,20)(13,17)(15,18)(16,21)(19,23)(22,24)(25,27,29,34)(26,31,30,37)(28,36,35,33)(32,40,38,39)(9,11)(10,15)(12,19)(13,18)(14,17)(16,23)(20,22)(21,24)(25,26)(27,31)(28,32)(29,30)(33,39)(34,37)(35,38)(36,40) involution — undirected(1,4,5,2)(3,7,8,6)(9,12)(10,16)(11,19)(13,21)(14,22)(15,23)(17,20)(18,24)(25,28,29,35)(26,32,30,38)(27,33,34,36)(31,39,37,40)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.