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