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