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