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