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