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)(11,19)(12,23)(13,15)(14,24)(16,22)(17,21)(18,20)(25,26)(27,33)(28,37)(29,34)(30,40)(31,32)(35,36)(38,39)(2,3)(6,7)(9,11,15,22)(10,16,13,19)(12,14,21,20)(17,24,23,18)(26,32)(29,37)(33,40)(36,39)(1,3,5,2)(4,7,8,6)(9,10,15,13)(11,16,22,19)(12,23,21,17)(14,18,20,24)(25,27,31,30)(26,33,32,40)(28,38,34,35)(29,36,37,39)(1,4,5,8)(2,6,3,7)(9,12,15,21)(10,17,13,23)(11,20,22,14)(16,18,19,24)(25,28,31,34)(26,29,32,37)(27,35,30,38)(33,39,40,36)(9,13,15,10)(11,16,22,19)(12,23,21,17)(14,24,20,18)(25,29)(26,34)(27,36)(28,32)(30,39)(31,37)(33,35)(38,40)(9,14,15,20)(10,18,13,24)(11,21,22,12)(16,17,19,23)(25,30,31,27)(26,33,32,40)(28,38,34,35)(29,39,37,36)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.