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