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