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