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