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