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