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