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