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