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