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