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