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