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