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