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