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