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