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