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