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