One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6,9,7)(8,11,12,10)(13,14,16,18)(15,17,19,20)(23,28)(24,26)(8,12)(10,11)(13,14)(15,17)(16,18)(19,20)(21,22,25,27)(23,24,28,26)(6,7)(10,11)(15,19)(17,20)(21,23,25,28)(22,26,27,24)(1,2)(3,4)(5,7,9,6)(8,11,12,10)(13,14)(15,20)(16,18)(17,19)(21,23)(22,24)(25,28)(26,27)(5,8)(6,10)(7,11)(9,12)(13,15)(14,17)(16,19)(18,20)(21,24)(22,23)(25,26)(27,28) involution — undirectedA 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.