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