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