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