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