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