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