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