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