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