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