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