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