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