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