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