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