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