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