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