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