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