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