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