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