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