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