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