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)(25,26,29,32)(27,31,35,39)(28,37,30,33)(34,36,40,38)(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)(28,36)(29,35)(30,38)(32,39)(33,34)(37,40)(1,4,5,3)(2,6,7,8)(25,26)(27,34)(28,33)(29,32)(30,37)(31,38)(35,40)(36,39)(10,15)(14,17)(16,23)(22,24)(26,32)(27,35)(33,37)(36,38) involution — undirected(9,12,13,21)(10,16,15,23)(11,18,19,20)(14,22,17,24)(25,28)(26,33)(29,30)(31,39)(32,37)(36,38)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.