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