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