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