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