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