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