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