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