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