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)(27,33,34,29)(28,36,37,32)(35,38,40,39)(1,2)(3,4)(5,6)(7,8)(10,12)(15,17)(16,20)(22,23)(26,31)(27,34)(28,37)(38,39) involution — undirected(2,6)(4,7)(13,21)(16,20)(18,24)(22,23)(26,31)(29,33)(32,36)(38,39) involution — undirected(9,11)(10,15)(12,17)(13,18)(14,19)(16,22)(20,23)(21,24)(25,27)(26,29)(28,35)(30,34)(31,33)(32,38)(36,39)(37,40) involution — undirected(1,3)(2,7)(4,6)(5,8)(9,12,14,10)(11,17,19,15)(13,20,21,16)(18,23,24,22)(25,28,30,37)(26,32,31,36)(27,35,34,40)(29,38,33,39)(1,4,5,7)(2,3,6,8)(9,13,14,21)(10,16,12,20)(11,18,19,24)(15,22,17,23)(25,29)(26,27)(28,38)(30,33)(31,34)(32,35)(36,40)(37,39)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.