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