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