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