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