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