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