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