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