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