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