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