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