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