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