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