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