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