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