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