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