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