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