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)(12,20,21,15)(18,22,24,23)(25,26)(27,32)(28,38)(29,34)(30,35)(31,36)(33,39)(37,40)(9,11,13,19)(10,14,16,17)(12,18,21,24)(15,22,20,23)(25,27)(26,32)(28,29)(30,37)(31,39)(33,36)(34,38)(35,40)(2,6)(7,8)(25,28,29,27,30,39,31,37)(26,33,34,40,35,38,36,32)(1,3,5,4)(2,7,6,8)(9,12,13,21)(10,15,16,20)(11,18,19,24)(14,22,17,23)(25,29,30,31)(26,34,35,36)(27,28,37,39)(32,38,40,33)(1,4,5,3)(2,8,6,7)(11,19)(14,17)(18,24)(22,23)(25,28,29,27,30,39,31,37)(26,33,34,40,35,38,36,32)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.