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