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