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