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