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