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