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