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