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