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