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