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