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