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