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