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