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