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