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