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