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