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