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