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