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