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