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