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