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