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