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