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