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