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