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