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)(11,13)(12,16)(14,18)(15,22)(17,23)(19,24)(20,21)(25,26,32,30)(27,36,38,33)(28,34,29,39)(31,35,37,40)(1,2,5,4)(3,6,8,7)(9,11,14,17)(10,13,18,23)(12,20,22,19)(15,24,16,21)(25,27)(26,33)(28,31)(29,37)(30,36)(32,38)(34,40)(35,39)(1,2,5,4)(3,7,8,6)(9,12,14,22)(10,15,18,16)(11,19,17,20)(13,21,23,24)(25,28,32,29)(26,34,30,39)(27,31,38,37)(33,40,36,35)(1,3,5,8)(2,6,4,7)(9,12)(10,16)(11,20)(13,21)(14,22)(15,18)(17,19)(23,24)(25,29,32,28)(26,34,30,39)(27,37,38,31)(33,40,36,35)(1,3)(2,7)(4,6)(5,8)(9,11)(10,13)(12,19)(14,17)(15,21)(16,24)(18,23)(20,22)(25,30,32,26)(27,36,38,33)(28,39,29,34)(31,35,37,40)(1,4,5,2)(3,7,8,6)(9,13)(10,17)(11,18)(12,21)(14,23)(15,20)(16,19)(22,24)(25,31,32,37)(26,35,30,40)(27,28,38,29)(33,39,36,34)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.