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