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