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