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