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