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