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