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