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