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