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