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