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