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)(11,19,21,16)(12,22,23,17)(13,18,24,20)(25,26,30,35)(27,32,36,31)(28,33,39,38)(29,34,40,37)(3,7)(5,8)(10,15)(12,23)(16,19)(18,20)(27,36)(28,39)(31,32)(33,38) involution — undirected(1,2)(3,5)(4,6)(7,8)(25,27)(26,31)(28,37)(29,38)(30,36)(32,35)(33,40)(34,39) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,11,14,21)(10,16,15,19)(12,20,23,18)(13,22,24,17)(25,27)(26,32)(28,37)(29,33)(30,36)(31,35)(34,39)(38,40)(1,2)(3,5)(4,6)(7,8)(9,12,14,23)(10,17,15,22)(11,20,21,18)(13,19,24,16)(25,28)(26,33)(27,37)(29,32)(30,39)(31,40)(34,36)(35,38)(9,13)(10,18)(11,17)(12,19)(14,24)(15,20)(16,23)(21,22)(25,29)(26,34)(27,38)(28,32)(30,40)(31,39)(33,36)(35,37) 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.