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