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