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