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