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