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