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