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