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