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