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