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