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)(11,13)(12,15)(14,20)(16,18)(17,22)(19,23)(21,24)(25,26,30,33)(27,31,36,39)(28,29,37,32)(34,35,40,38)(2,3)(6,7)(9,11)(10,16)(12,13)(14,19)(15,18)(17,23)(20,21)(22,24)(25,27,30,36)(26,31,33,39)(28,34,37,40)(29,35,32,38)(2,3)(6,7)(10,12)(11,18)(17,20)(19,24)(25,28,30,37)(26,32,33,29)(27,34,36,40)(31,38,39,35)(1,2,5,3)(4,6,8,7)(9,12,15,10)(11,13,18,16)(14,20,22,17)(19,21,24,23)(25,28)(26,29)(27,34)(30,37)(31,35)(32,33)(36,40)(38,39)(1,3,5,2)(4,6,8,7)(9,13)(10,11)(12,18)(14,21)(15,16)(17,19)(20,24)(22,23)(25,27)(26,31)(28,34)(29,35)(30,36)(32,38)(33,39)(37,40)(1,4,5,8)(2,6,3,7)(9,14,15,22)(10,17,12,20)(11,19,18,24)(13,21,16,23)(25,29)(26,28)(27,35)(30,32)(31,34)(33,37)(36,38)(39,40)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.