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