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