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