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)(17,21)(19,23)(22,24)(25,26)(27,34)(28,36)(29,31)(30,32)(33,38)(35,39)(37,40)(3,7)(5,8)(9,11)(10,14)(12,19)(13,18)(15,16)(17,22)(20,23)(21,24)(25,27,31,30)(26,32,29,34)(28,37,38,35)(33,40,36,39)(1,2)(3,5)(4,6)(7,8)(10,15)(11,18)(17,20)(19,24)(26,29)(28,38)(32,34)(35,37) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,10)(11,16)(12,17)(13,15)(14,18)(19,23)(20,21)(22,24)(25,28)(26,33)(27,35)(29,36)(30,37)(31,38)(32,39)(34,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,11)(10,16)(12,19)(13,18)(14,15)(17,23)(20,22)(21,24)(25,29,31,26)(27,34,30,32)(28,36,38,33)(35,40,37,39)(9,12,13,21)(10,17,15,20)(11,19,18,24)(14,22,16,23)(25,30,31,27)(26,34,29,32)(28,37,38,35)(33,40,36,39)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.