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